Image recording methods of forming an image on a recording medium such as paper based on image data signals include those by an electrographic system, a sublimation type or fusion type heat transfer system, an inkjet system, or the like. Among them, the inkjet system can be carried out by using an inexpensive device and, since an image is formed directly on a recording medium by ejecting ink only onto a required image area, ink can be used efficiently and running costs are low.
As one of the inkjet systems, there is a recording system using an inkjet recording ink which is curable by irradiation with an actinic energy ray. According to this method, by curing ink droplets, the productivity of printing can be enhanced, and a sharp image can be formed. Further, it is also possible to fabricate printed matter in which an image is formed by such an inkjet method.
From the viewpoint of improving curability and sensitivity, Japanese Patent Application Laid-Open (JP-A) No. 2004-339480 discloses a radiation-curable ink composition including an initiator and a polyhedral oligomeric silsesquioxane.
JP-A No. 2010-13514 discloses a composition for optical nanoprinting, the composition including a polymerization initiator, a polymerizable compound, and silsesquioxane, for the purpose of improving the imprint property after thermal curing, the adhesion to substrate, heat resistance, and surface hardness.